title: Conformational changes in human prolyl-tRNA synthetase upon binding of the substrates proline and ATP and the inhibitor halofuginone.
abstract: Aminoacyl-tRNA synthetases recognize cognate amino acids and tRNAs from their noncognate counterparts and catalyze the formation of aminoacyl-tRNAs. Halofuginone (HF), a coccidiostat used in veterinary medicine, exerts its effects by acting as a high-affinity inhibitor of the enzyme glutamyl-prolyl-tRNA synthetase (EPRS). In order to elucidate the precise molecular basis of this inhibition mechanism of human EPRS, the crystal structures of the prolyl-tRNA synthetase domain of human EPRS (hPRS) at 2.4 Å resolution (hPRS-apo), of hPRS complexed with ATP and the substrate proline at 2.3 Å resolution (hPRS-sub) and of hPRS complexed with HF at 2.62 Å resolution (hPRS-HF) are presented. These structures show plainly that motif 1 functions as a cap in hPRS, which is loosely opened in hPRS-apo, tightly closed in hPRS-sub and incorrectly closed in hPRS-HF. In addition, the structural analyses are consistent with more effective binding of hPRS to HF with ATP. Mutagenesis and biochemical analysis confirmed the key roles of two residues, Phe1097 and Arg1152, in the HF inhibition mechanism. These structures will lead to the development of more potent and selective hPRS inhibitors for promoting inflammatory resolution.
authors.affiliation: Department of Biosystems and Biotechnology, Korea University, Anam-dong 5, Seongbuk-gu, Seoul 136-701, Republic of Korea.
authors.forename: Jonghyeon
authors.initials: J
authors.lastname: Son
authors.forename: Eun Hye
authors.initials: EH
authors.lastname: Lee
authors.forename: Minyoung
authors.initials: M
authors.lastname: Park
authors.forename: Jong Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Junsoo
authors.initials: J
authors.lastname: Kim
authors.forename: Sunghoon
authors.initials: S
authors.lastname: Kim
authors.forename: Young Ho
authors.initials: YH
authors.lastname: Jeon
authors.forename: Kwang Yeon
authors.initials: KY
authors.lastname: Hwang
mesh_terms: D000255:Adenosine Triphosphate / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics; D000604:Amino Acyl-tRNA Synthetases / Q000037:antagonists & inhibitors* / Q000737:chemistry*; D020134:Catalytic Domain / Q000187:drug effects / Q000235:genetics; D018360:Crystallography, X-Ray; D005975:Glutamate-tRNA Ligase / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics; D006801:Humans; D016296:Mutagenesis; D010880:Piperidines / Q000737:chemistry / Q000494:pharmacology*; D011392:Proline / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics; D011485:Protein Binding / Q000187:drug effects / Q000235:genetics; D011487:Protein Conformation / Q000187:drug effects; D011500:Protein Synthesis Inhibitors / Q000737:chemistry / Q000494:pharmacology; D052999:Quinazolinones / Q000737:chemistry / Q000494:pharmacology*; D013379:Substrate Specificity / Q000187:drug effects / Q000235:genetics
chemical_list: D010880:Piperidines; D011500:Protein Synthesis Inhibitors; D052999:Quinazolinones; D000255:Adenosine Triphosphate; D011392:Proline; D000604:Amino Acyl-tRNA Synthetases; C100134:prolyl T RNA synthetase; D005975:Glutamate-tRNA Ligase; C010176:halofuginone
keywords: drug design; glutamyl-prolyl-tRNA synthetase; herbal inhibitor; inflammation; multisynthetase complex